Diazo-type developers

ABSTRACT

Developer compositions and their use in the development of 1- or 2-component diazo-type materials, said compositions containing as a solvent medium, formamide, mono- or dialkyl formamides, 2pyrrolidone, N-substituted derivatives of 2-pyrrolidone, sulfolane, dimethylsulphoxide, ethylene carbonate, gammabutyrolactone, and other organic compounds containing the structures FROM 0 TO ABOUT 95 PERCENT OF WATER, AND AN ALKALINE REACTING DEVELOPING AGENT, WITH OR WITHOUT AN AZO COUPLER.

United States Patent Raiiqul Islam;

Sidney G. Garnish, both of London, England 754,468 .Aug. 21,1968

Oct. 26, 1971 GAF Corporation New York, N .Y.

[72] inventors [21] Appl. No. [22] Filed [45 Patented [73] Assignee [54] DIAZO-TYPE DEVELOPERS 2,789,904 4/1957 Benbrook et a1. 96/91 X 3,203,803 8/1965 Habib et a1. 96/91 3,255,007 6/1966 Kosar 96/91 X 3,303,028 2/1967 Aebiet al. 96/49X 3,360,369 12/1967 Amariti et 21... 96/91 X 3,397,985 8/1968 Hendrickx 96/91 3,406.072 10/1968 Welch 96/91 3,446,620 5/1969 Parker 96/49 OTHER REFERENCES Dinaburg; M. S., Photosensitive Diazo Cpds," 1964, p. 126.

Primary Examiner-Charles L. Bowers, Jr. Anorneys-Walter G. Hensel, Walter C. Kehm and Samson B.

Leavitt ABSTRACT: Developer compositions and their use in the development of 1- or 2-component diazo-type materials, said compositions containing as a solvent medium, formamide, monoor dialkyl formamides, 2-pyrrolidone, N-substituted derivatives of 2-pyrr0lidone, sulfolane, dimethylsulphoxide, ethylene carbonate, gamma-butyrolactone, and other organic compounds containing the structures from 0 to about 95 percent of water, and an alkaline reacting developing agent, with or without an azo coupler.

This invention relates to liquid developers for light-sensitive diazo-type copying material.

Conventional development of diazo-type materials in copying processes can be divided into three categories, known as ammonia development, moist or semidry development, and thermal development.

The diazo-type materials used with ammonia and semidry development processes are known as two-component and one-component materials respectively.

ln the ammonia process, a solution containing the diazosensitizer, viz. the diazonium compound, one or more couplers and an organic acid is coated upon a support sheet. The coated sheet is exposed to light in contact with a translucent original. The latent image so obtained is developed by contacting the sheet with ammonia vapor, which neutralizes the acid stabilizer and promotes diazo-type coupling to produce a dye image of the original.

In the moist or semidry process, it is customary for the diazosensitizer to be coated upon a support sheet in conjunction with stabilizer agents. Exposure is carried out as before and the latent image is developed by passing the sheet through an aqueous buffered solution containing one or more couplers or, alternatively, by applying the solution to the surface of the sheet.

Both of these processes have disadvantages. in the ammonia process, it is the ammonia fumes, which require ducting on the machinery used and extra ventilation in the rooms where the process is carried out. The ducting prevents the machinery used from being easily moved and adds considerably to the expense of installation.

Known developer solutions employed in the moist or semidry process have disadvantages which are due to the water contained in them, because these solutions tend to suffer loss of water by evaporation, which can cause crystallization of the developer chemicals and subsequent clogging of the apparatus. Because of this and the tendency for the developer solution to become polluted with dye produced in the reaction, it is conventional operating practice to empty the developer apparatus at the end of each working day and wash the tray and rollers of the applicator system in the apparatus. Also, copies made by this process require drying and tend to curl badly, especially if the developer solution is applied to only one side of the sheet.

The aforementioned disadvantages are overcome by the thermal development process, in which all the components required to form the image are present upon the support sheet and the image obtained by exposure is developed by the application of heat to the sheet. However, this process in its turn suffers from the disadvantages of the effect of the heat on the support sheet and the difiiculty of preventing premature coupling at ambient temperatures.

An object of this invention is to overcome or minimize these disadvantages.

The present invention accordingly provides an improved developer for a system where the diazonium compound is coated without couplers, known as a one-component system, or where the diazonium compound is coated together with one or more couplers, known as a two-component system. This developer comprises a developing agent and, as a solvent, at least one liquid or low-melting, water-soluble compound selected from formamide, monoalkyl and dialkyl formamides, 2-pyrrolidone, N-substituted and other derivatives of 2-pyrrolidone, sulfolane dimethyl sulfoxide ethylene carbonate, gamma-butyrolactone and other organic compounds containing the structures Y and having a solvent action.

In accordance with one preferred feature of the invention, the solvent comprises at least one compound of the formula:

/R, HJLN where R and R, are the same or different and each represents a hydrogen atom or an alkyl radical, preferably containing 1 to 4 carbon atoms.

In accordance with a particular embodiment of the invention, the developer is a nonaqueous composition and the solvent component is provided entirely by organic materials of the kinds defined above. Preferably, the solvent is formamide. For two-component material, the developing agent normally comprises a base; for one-component material, it also contains a coupler and an antioxidant.

Formamide, wherein R, and R, in the general formula are both hydrogen, is preferred as the solvent in many formulations, but the developers of the invention can include more than one of the compounds mentioned, if required.

Other organic solvents of the present invention, that is to say, the solvent components which can be used apart from amides, are typified by organic substances of a variety of structures which all have at least one doublebonded oxygen atom therein, together with a melting point at most only slightly above room temperature and preferably under 25 C. and also a high dielectric constant; also, it is preferably for the substance to exhibit good solubility for conventional azo couplers, such as resorcinol and phloroglucinol and to have low volatility; desirably having a considerably lower vapor tension than water, and soluble therein.

The formulas of certain of these other organic solvent substances of the invention, which all include the typical doublebonded oxygen atom mentioned above, are as follows:

Some of the properties of these solvents with water for comparison are set out in the following Table:

Dielectric Solubility of B.P. M.P. constant phloroglu- Develop- Solvent 0.) C.) C.) clnol ment rate Examples 24-25 and E and F relate to development of twocomponent material;

All the amounts are given in parts by weight.

In accordance with another particular embodiment of the invention, following the discovery that the water-soluble organic solvent or solvents can be used with advantage in diazotype development, it has also been discovered that it is only necessary to use small amounts, e.g. of the order of 5 percent 5 by volume and upwards, of the organic solvent or solvents, in

order to obtain effective and satisfactory development, the EXAMPLEl I balance of the solvent component being water; the proportion Formamids 90 Paris of water can be varied over wide limits, however as illustrated 5 Sodium formate 5 parts in the examples given below. It has been established that there Thioureadioxide umingamino can be advantages, which may be manifest at various points in methane sulfinic acid) 05 parts the development process or in relation to various aspects of the diazo-type system, in having water in the developer. The

invention thus provides both nonaqueous developers and EXAMPLE 2 water-containing developers and the choice between these two kinds to be made in any instance is largely governed by zg 'f I 2 P t the particular advantages which the operator wishes to benefit iss: 7 52: from' Thioureadioxide 0.3 parts According to another aspect of the invention, a method of developing one-component and two-component diazo-type 2O material comprises applying to the material a developer of the EXAMPLE present invention, as above defined.

The invention, more specifically, includes also a method of 5x323211 making a copy of an original, which comprises exposing a sup- 2 5 Sodium benzoate 10 parts port sheet, which is sensitized by means of a composition in- Thiw'eadhxide P cluding a diazosensitizer, in contact with the original to be copied, to form a latent image on the support sheet, and apply ing to the expos d side of the support sheet a composition EXAMPFE containing a diazo-type developing agent in a solvent selected from formamide and the N-monoalkyl and N,N-dialkyl deriva- Formamide 80 P tives with certain organic developer solvents, Pam

Phloroglucmol 2.5 parts A preferred developer formulation of the invention, suitable f i 5 P for one-component material, desirably contains resorcinol, Thmmudwx'd" phloroglucinol or a simple derivative thereof as an azo coupler, an antioxidant and either a nitrogen base as discussed above or an alkali metal salt of a carboxylic or other weak acid EXAMPLE (or both); suitable salts include sodium benzoate, formate, acetate, propionate, succinate and maleate; nitrogen base car- 40 Formamide 85 parts boxylic acids which are suitable include aminopropionic acid s i'fy sg zg 2 P (alanine), 4-aminobutyr1c ac d and piperldme-4-carboxylic sodiunfpmpionm 5 :ZL: acid. In general, any conventional azo coupler can be used, Thioureadioxidc M5 the substance used preferably being selected from phenols, phenol derivatives, naphthols, naphthol derivatives, aromatic amines and aliphatic compounds containing at least one activated methylene group. Specific azo couplers, apart from the EXAMFLE 6 phenols mentioned, are 4-chlororesorcinol, 2,3-dihydroxynaphthalene, 2-oxy-3-naphthoic acid ethanolamide, 4,4- Formflmide 90 parts methylene-dianiline dihydrochloride and acetoacetbenzylafigfgfi zg 2 3:2: Thioureadioxide 0.5 parts Other weak acids whose salts can be used include boric acid and diand triphosphates and, in general, any acid having a K- value lower than 2X10. The purpose of these salts is to pro- EXAMPLE vide a buffer action,

A developer of this invention has a faster development time Fmmamide 99 Pam than conventional aqueous developers and gives full develop- Resorcinol 2 parts ment at a lower quantitative rate of application, for example, f" "9' Pam 5-6 g./m. instead of 10-11 g./m. Also, the developer can be 2223:3323 :ggz M t: formulated so as to be more stable than conventional aqueous developers and because the evaporation of the organic solvent(s) used or included is negligible, developers can readily EXAMPLE 8 be provided wherein substantially no crystallization of dissolved components takes place, even after extended periods of 6 5 Formamide 90 part storage, and no pollution occurs from the dye of the diazophlomglucinol 5 pans type material. Where the developer is a nonaqueous composi- Piperidine-4-carboxylic acid 5 parts tion based upon one or more organic solvents and is applied in controlled limited quantities by any suitable apparatus, a substantially dry print is obtained and, even when only one side of the support sheet is treated, there is no tendency for the sheet EXAMPLE 9 A to curl. g 'g'g 83 The invention is further described in the following Exame y e Z ples, in which: Phlorogl cinol 5 parts Examples l-23 and A-D relate to development of one-com- Thiwmdmide P ponent material;

EXAMPLE Formsrnide 85 pans Furfuraldehyde 5 pans Borax 5 parts Sodium molybdate 2 parts Resorcinol 2 pans Phloroglucinol 2 pans Thioureadioxide 0.5 parts EXAMPLE ll 2-Pyn'olidone 95 pans Phloroglucinol 5 pans EXAMPLE N-methyl-Z-pyrrolidonc 95 pans Phloroglucinol 5 parts EXAMPLE l3 N- vinyl-2-pyrrolidone 95' pans Phloroglucinol 3 pans EXAMPLE l4 Gamma-butyrolaetone 95 parts Phluroglucinol 3 pans Dicthanolamine 2 parts EXAMPLE l5 s Dimethyl sulfoxide 95 pans Phloroglucinol 3 pans EXAMPLE l6 Sulfolane 90 pans Phloroglucinol 5 pans Triethanolamine 5 pans EXAMPLE l7 Ethylene carbonate 95 parts Phlomglucinol .5 pans EXAMPLE l8 Ethylene carbonate 45 parts 2-pyrrolidone 50 pans Rewrcinol 5 pans EXAMPLE l9 Dirncrhyl sulfoxide 50 parts Gamma-butyro-lactone 45 pans Rcsorcinol 5 parts EXAMPLE 20 Dimethyl sulfoxide 40 parts Gamma-butyro-lactone 30 parts Sulfolane 25 pans Phloroglucinol 3 parts EXAMPLE 2| Formamidc 60 pans Z-pyrrolidone 3S pans Sodium bcnzoate 5 parts Thioureadioxide (lmino-amino-methane sullinic acid) 0.25 pans- EXAM PLE 22 Formamide 50 pans Sullolane 43 pans Sodium benzoate 7 parts Thlourusdloxide 0.4 parts EXAM PLE 23 Z-Pyrrolldona 85 parts Water l0 parts Sodium benzostn 3 parts Phloroglucinol 2.5 parts The developers of the above examples develop conventional one-component diazo-type materials at room temperature very rapidly to give a dark image on a white background. Examples 6, 7, l8and l9are particularly suitable for developing prints on sensitized tracing paper. Examples 9and lOare suitable for developing one-component diazo-type material containing polyvinyl alcohol in the surface coating. The borax and the aldehydes combine with the polyvinyl alcohol to give a dry surface.

Examples of conventional one-component materials are as follows: EXAMPLE A A white-base paper is coated with a sensitizing liquid of the following composition:

2.5-Dimethoxy-d-para-methylphenyll .5 parts thlobenzene diazoniuln chlurozincatc Tartaric or citric acid 0.5 pans Water. to make I00 parts EXAMPLE B A tracing paper is coated with a sensitizing liquid of the following composition:

2.5-Diethoxy-4-para-methylphenyl- 2.5 parts thiobenzene diazonium chlorozlncate Citric acid 0.5 pans Gelatine L5 parts Water 70 parts Ethanol 25 parts n-Butanol 10 parts EXAMPLE C A tracing paper is coated with a sensitizing liquid of the following composition:

2,5-Dicthoxy-4-para-methylphenylthiobenzene diazonlum borofluoride 3 pans Polyvinyl alcohol (*TElvanol" 5 l-OS) 5 parts (Elavanol" is a du Pont Trade Mark) Water 70-l00 pans Ethanol 30 parts EXAMPLED A tracing paper having a partially hydrolysed cellulose acetate surface is coated with a sensitizing liquid of the follow ing composition:

3-chloro-4-dimethylamino-benzine Formamide 80 parts N-methylformamide 5 parts 2-Amlno-pyridine 15 parts EXAM PLE 2B Formumldl 80 purtl l-Amlnu-pyrldlnn l purtu Dllmprupanolumlno 10 parts EXAM PLE 29 Formamidc 80 parts Sodium acetate l0 parts Z-Amino-pyridine 10 parts EXAMPLE 30 Forrnamide 80 parts LZ-Dirnorpholinoethane 10 parts Triisopropanolamine 10 parts EXAMPLE 3! Formamide 75 parts N.N-dimethylformamide parts l.2-Dimorpholinoethane 15 parts Borax 5 parts EXAM PLE 32 Dimethyl sulfoxide 85 parts Diethanolamine l5 parts EXAMPLE 33 Ethylene carbonate 90 parts Diethanolamine parts EXAM PLE 34 Z-Pyrrolidone 80 parts l.2-Dimorpholinoethanc 20 parts EXAMPLE 3S Sulfolane 80 parts 4-Amino-pyridine 10 parts Diisopropanolamine 10 parts The developers of examples 24-35each develop conven tional two-component materials such as are shown in the following examples E and F to give a blue image (example E) or a black image (example F) F) on a white background. Example E A white-base paper is coated with sensitizing liquid of the following composition:

Para-diethylarnino-benzene diazonium chloro-zincate 1.9 parts 2,7-Dihydroxynaphthalene-3.6-

disulfonic acid 2 parts Calcium chloride l0 parts Citric acid l parts Water. to make I00 parts ('Alternatively, the disodium salt can be used).

EXAMPLE F A white base paper is coated with a sensitizing liquid with the following composition:

Paradiethylaminobenzene diazonium chloro-zincate 2.3 parts 2,7-Dihydroxynaphthalene-3,6-

disulfonic acid 2 parts fi-l-lydroxycthylresorcinol 5 parts Resorcinol I parts Tarturic acid I parts Calcium chloride 10 parts Urea 3 parts Water. to make I00 part1 ('Altematively, the disodium salt can be used).

EXAMPLE 36 The following formulation contains an approximately 50 percent aqueous composition:

Farmamlde I00 ml.

Phlorogluclnol 4 g. Sodium bcnzoate I0 g. Thiourea dioxide 0.5 g. Sodium isopropyl naphthalene sulfonate 0.5 g.

Formamlde, ml 100 95 75 50 25 5 Water, m1 5 25 50 75 95 Phlorogluclnol, g- 4 4 4 4 4 4 Sodium benzoate, g. 10 10 10 10 10 10 Thlourea dioxide, g 0, 5 0. 5 0. 5 0. 5 0. 0. 5 Aerosol 08, g 0. 5 0. 5 0. 5 0. 5 0. 5 0. 5

Using a grooved roller applicator device, these solutions were used to develop standard neutral moist papers. All worked adequately. The developer solutions were then allowed to stand open in evaporating dishes for 24 hours. The solutions were again used to develop prints. All were adequate. They were then left open for 72 hours. The solutions of examples 37-41 were essentially unchanged in appearance, although those of examples 40, 41 had lost volume. All, however, developed prints very well. The solution of ex ample 42, which was the most dilute initially, showed considerable crystal formation and loss of volume, but would still develop a print.

It appeared from the results obtained that as little as 5 percent high-boiling, water-miscible solvent in a moist developer, substantially retards crystal formation and allows a moist diazo-type machine to operate for a much longer period, without a cleanup, than would a moist developer containing only water as solvent.

EXAMPLES 43 AND 44 Gamma butyro1actone,ml 50 10 to 50 4 4 10 10 0. 5 0. 5 0. 5 0. 5

where R, and R, are the same or different and each represents I ing at least one activate methylene group.

7. A composition according to claim 1, in which the base compound is, an alkali metal salt of a weak acid.

8. A composition according to claim 7, in which the salt is selected from the group consisting of sodium benzoate, formate, acetate, propionate, succinate and maleate.

9. A composition according to claim 7, in which the salt is selected from the group consisting of the alkali metal salts of aminopropionic acid, 4-aminobutyric acid and piperidine-4- carboxylic acid.

10. A method of developing a one-component diazo-type material to produce a positive azo dye image of the original, which comprises applying to the material, after imagewise exposure to light, a composition as defined in claim 20.

11. A method of making positive copy of an original, which comprises exposing a support sheet, which is sensitized by means of a composition including a diazosensitizer, in contact with the original to be copied, to form a latent image on the support sheet, and applying to the exposed side of the support sheet a composition as described in claim 20 wherein the solvent is formamide, N-monoalkyl formamide or N-dialkyl formamide, to obtain a copy of the original.

12. A method according to claim 11, in which the composition containing diazo-type developing agent is applied to the support sheet in an amount of 5-6 g./m. 

2. A composition according to claim 1, in which the solvent is a compound of the general formula: where R1 and R2 are the same or different and each represents a hydrogen atom or an alkyl radical of from one to four carbon atoms.
 3. A composition according to claim 2, in which the solvent is formamide.
 4. A composition according to claim 1, in which the base is a compound selected from the group consisting of mono-ethanolamine, diethanolamine, triethanolamine, 1,2-dimorpholinoethane, diisopropanolamine, triisopropanolamine and 2-aminopyridine.
 5. A composition according to claim 4 in which the base is present in formamide solution.
 6. A composition according to claim 1, in which the azo coupler is selected from the group consisting of phenols, naphthols, aromatic amines and aliphatic compounds containing at least one activated methylene group.
 7. A composition according to claim 1, in which the base compound is, an alkali metal salt of a weak acid.
 8. A composition according to claim 7, in which the salt is selected from the group consisting of sodium benzoate, formate, acetate, propionate, succinate and maleate.
 9. A composition according to claim 7, in which the salt is selected from the group consisting of the alkali metal salts of aminopropionic acid, 4-aminobutyric acid and piperidine-4-carboxylic acid.
 10. A method of developing a one-component diazo-type material to produce a positive azo dye image of the original, which comprises applying to the material, after imagewise exposure to light, a composition as defined in claim
 1. 11. A method of making a positive copy of an original, which comprises exposing a support sheet, which is sensitized by means of a composition including a diazosensitizer, in contact with the original to be copied, to form a latent image on the support sheet, and applying to the exposed side of the support sheet a composition as described in claim 1 wherein the solvent is formamide, N-monoalkyl formamide or N-dialkyl formamide, to obtain a copy of the original.
 12. A method according to claim 11, in which the composition containing the diazo-type developing agent is applied to the support sheet in an amount of 5-6 g./m.2. 